Xamarin / iOS SharedAccessoryManager.ShowBluetoothAccessoryPicker Fails

I'm porting working Swift code to Xamarin for my project. Every time I call this function, it fails and the accessory picker dialog doesn't show.

EAAccessoryManager.SharedAccessoryManager.ShowBluetoothAccessoryPicker(predicate, completion)

Here's some things I've confirmed:

  • BT Radio is on
  • Info.plist has Supported external accessory protocols
  • Tried ensuring call is done on UI thread
  • Tried calling directly from Button click event
  • The same basic code in Swift / Xcode works fine

Xamarin:

        EAAccessoryManager.SharedAccessoryManager.ShowBluetoothAccessoryPicker(null, completion: ((Foundation.NSError error) => {
            Console.WriteLine("My callback");   
            if (error != null) {
                Console.WriteLine(String.Format("Error code: {0} Desc: {1}", error.Code, error.DebugDescription));
                Console.WriteLine("Failed? " + EABluetoothAccessoryPickerError.Failed.ToString());
                Console.WriteLine("Failed? " + Convert.ToInt64(EABluetoothAccessoryPickerError.Failed));
            }
        }));

Xcode / Swift:

        EAAccessoryManager.sharedAccessoryManager().showBluetoothAccessoryPickerWithNameFilter(nil) { (error) -> Void in
        if error != nil {
            NSLog("Error code: \(error!.code) \(error.debugDescription)")
        }
    }

The Xamarin code doesn't show the picker and will always fail.

2016-04-05 19:54:02.136 ASGDemo.iOS[6383:2146384] Connect Clicked
2016-04-05 19:54:06.139 ASGDemo.iOS[6383:2146384] BTM: attaching to BTServer
2016-04-05 19:54:09.157 ASGDemo.iOS[6383:2146384] BTM: session attach called back with BT_SESSION_ATTACHED (fffffed0)
2016-04-05 19:54:09.158 ASGDemo.iOS[6383:2146384] BTM: attemping to re-attach in 1 seconds
2016-04-05 19:54:09.242 ASGDemo.iOS[6383:2146384] My callback
2016-04-05 19:54:09.250 ASGDemo.iOS[6383:2146384] Error code: 3 Desc: Error Domain=EABluetoothAccessoryPickerErrorDomain Code=3 "(null)"
2016-04-05 19:54:09.253 ASGDemo.iOS[6383:2146384] Failed? Failed
2016-04-05 19:54:09.254 ASGDemo.iOS[6383:2146384] Failed? 3